Hey i need help im doing OCR A and ive just done this Q and i dont get it:

3-methylheptane reacts with chlorine in presence of UV to give several strucural isomers of C8H17Cl

The answer is 8, but i thought 16 because you can move the Cl to 4 diff places, then a methyl gp in 5 dff places etc etc. its only 1 mark so it must be obvious? I dont get how to work that out so easily... Or why its just 8 ta guyz hope exams are doing okay

(Original post by Georgiam247)
Hey i need help im doing OCR A AS and ive just done this Q and i dont get it:3-methylheptane reacts with chlorine in presence of UV to give several strucural isomers of C8H17ClThe answer is 8, but i thought 16 because you can move the Cl to 4 diff places, then a methyl gp in 5 dff places etc etc. its only 1 mark so it must be obvious? I dont get how to work that out so easily... Or why its just 8 ta guyz hope exams are doing okay

Hi guys I have a CCEA problem, kinda hoping one of you could help me out?

Okay so thats the stimulus of the question. On the next page it asks "explain why the sulphuric acid must be added cautiously with stirring".

So I was thinking first because it might be a very reactive....reaction. You know, to dull down any explosions, purely because that got me marks in GCSEs. But now I'm thinking it might be because you dont want to add excess acid, so you get just the right amounts of reactants? Is that right or am i missing some really obvious answer?

(Original post by Millie-3)Hi guys I have a CCEA problem, kinda hoping one of you could help me out?

Okay so thats the stimulus of the question. On the next page it asks "explain why the sulphuric acid must be added cautiously with stirring".

So I was thinking first because it might be a very reactive....reaction. You know, to dull down any explosions, purely because that got me marks in GCSEs. But now I'm thinking it might be because you dont want to add excess acid, so you get just the right amounts of reactants? Is that right or am i missing some really obvious answer?

Danke in advance!

the reaction is highly exothermic therefore the reactants aare combined slowly to avoid the release of too much heat energy which could damage the apparatus